The C23A system, an exmaple of quantitative control of plant growth associated with a data base

The architecture of the C23A (Chambers de Culture Automatique en Atmosphere Artificielles) system for the controlled study of plant physiology is described. A modular plant growth chambers and associated instruments (I.R. CO2 analyser, Mass spectrometer and Chemical analyser); network of frontal processors controlling this apparatus; a central computer for the periodic control and the multiplex work of processors; and a network of terminal computers able to ask the data base for data processing and modeling are discussed. Examples of present results are given. A growth curve analysis study of CO2 and O2 gas exchanges of shoots and roots, and daily evolution of algal photosynthesis and of the pools of dissolved CO2 in sea water are discussed

Simulation of Shaking Table Tests to Study Soil-Structure Interaction by Means of Two Different Constitutive Models

The paper presents the main results of a FEM 3-D model reproducing a physical model subjected to shaking table tests. The tests, performed at the EERC laboratory of Bristol University, have been simulated by means of a new numerical model based on a recent constitutive model characterized by isotropic and kinematic hardening and devoted to granular soil. The shaking table tests have been performed using: a six-degree of freedom shaking table; a shear-stack; a scaled one-storey steel frame; the Leigthon Buzzard Sand. The tests have been characterized by 11 shaking runs. As regards the 3-D numerical modeling, the linear elastic material has been considered for the structure, instead the soil has been modeled both with a cap-hardening Drucker-Prager model, often implemented in commercial codes, and with the above mentioned new constitutive model, implemented in the utilized FEM code by the Research Group of Catania University. Thanks to the great quantity of experimental data, the power of the proposed numerical model in simulation/prediction of dynamic soil-structure interaction can be verified and compared with the capability of other numerical models based on simpler constitutive models

Experimental, Theoretical and Numerical Evaluation of the Stiffness of a Soil-Foundation Model by Shaking-Table Test

A well-controlled test was carried out on a Leighton Buzzard sand-shallow foundation system by means of the six-degree-of-freedom shaking table available at the University of Bristol. The foundation consists of a concrete block located into a flexible shear-stack (Taylor et al., 1994) filled up to 1.00 m with the sand. During the test the block was subjected to a centered vertical load and to one direction sine dwell-type acceleration applied at the base of the shear stack. The static and dynamic sand properties were evaluated through different laboratory tests, among them resonant column tests, cyclic and monotonic loading torsional shear tests were performed (Mazzarella, 1999). A comprehensive network of accelerometers and displacement transducers was used to check the static and dynamic soil-foundation interaction (Maugeri et al., 1999a). The impedance functions (Gazetas, 1991) were evaluated and then compared with the experimental results. Finally, the experimental results were compared with the numerical ones obtained by means of a FEM code (Massimino, 1999) developed at the University of Catania

Hyperfractionated radiotherapy and chemotherapy for chidhood ependymoma: final results of the first prospective AIEOP (Associazione Italiana di Ematologia-Oncologia pediatrica) study

Purpose: A postsurgical “stage-based” protocol for ependymoma was designed. Methods and Materials: Children were given: (1) focal hyperfractionated radiotherapy (HFRT) if with no evidence of disease (NED), or (2) 4 courses with VEC followed by HFRT for residual disease (ED). HFRT dose was 70.4 Gy (1.1 Gy/fraction b.i.d.); VEC consisted of VCR 1.5 mg/m2 1/w, VP16 100 mg/m2/day 3, CTX 3 g/m2 d 1. When feasible, second-look surgery was recommended. Results: Sixty-three consecutive children were enrolled: 46 NED, 17 ED; the tumor was infratentorial in 47 and supratentorial in 16, with spinal metastasis in 1. Of NED patients, 35 of 46 have been treated with HFRT; 8 received conventionally fractionated radiotherapy, and 3 received no treatment. Of the 17 ED patients, 9 received VEC HFRT; violations due to postsurgical morbidity were as follows: HFRT only (2), conventionally fractionated radiotherapy (3) VEC (2), and no therapy (1). Objective responses to VEC were seen in 54%; objective responses to RT were seen in 75%. Overall survival and progression-free survival at 5 years for all 63 children were 75% and 56%, respectively; for the NED subgroup, 82% and 65%; and for the ED subgroup, 61% and 35%, respectively. All histologies were centrally reviewed. At multivariate analysis, grading, age, and site proved significant for prognosis. Conclusions: HFRT, despite the high total dose adopted, did not change the prognosis of childhood ependymoma as compared to historical series: New radiotherapeutic approaches are needed to improve local control. Future ependymoma strategies should consider grading when stratifying treatment indications

Study of the relationship between photosynthesis, respiration, transpiration, and mineral nutrition in wheat

The growth of wheat (triticum aestivum) was studied in an enclosed controlled environment for a period of 70 days. The exchange of gases (photosynthesis, respiration), water (transpiration) and the consumption of mineral elements (nitrogen, phosphorus, potassium) were continuously measured. The dynamical relations observed in the different physiological functions, under the influence of growth and in response to environment modifications are presented. The influence of carbon dioxide content during growth (normal or double percentage) was made clear

VisIVO - Integrated Tools and Services for Large-Scale Astrophysical Visualization

VisIVO is an integrated suite of tools and services specifically designed for the Virtual Observatory. This suite constitutes a software framework for effective visual discovery in currently available (and next-generation) very large-scale astrophysical datasets. VisIVO consists of VisiVO Desktop - a stand alone application for interactive visualization on standard PCs, VisIVO Server - a grid-enabled platform for high performance visualization and VisIVO Web - a custom designed web portal supporting services based on the VisIVO Server functionality. The main characteristic of VisIVO is support for high-performance, multidimensional visualization of very large-scale astrophysical datasets. Users can obtain meaningful visualizations rapidly while preserving full and intuitive control of the relevant visualization parameters. This paper focuses on newly developed integrated tools in VisIVO Server allowing intuitive visual discovery with 3D views being created from data tables. VisIVO Server can be installed easily on any web server with a database repository. We discuss briefly aspects of our implementation of VisiVO Server on a computational grid and also outline the functionality of the services offered by VisIVO Web. Finally we conclude with a summary of our work and pointers to future developments

Apparatus for providing vibrotactile sensory substitution of force feedback

A feedback apparatus for an operator to control an effector that is remote from the operator to interact with a remote environment has a local input device to be manipulated by the operator. Sensors in the effector's environment are capable of sensing the amplitude of forces arising between the effector and its environment, the direction of application of such forces, or both amplitude and direction. A feedback signal corresponding to such a component of the force, is generated and transmitted to the environment of the operator. The signal is transduced into a vibrotactile sensory substitution signal to which the operator is sensitive. Vibration producing apparatus present the vibrotactile signal to the operator. The full range of the force amplitude may be represented by a single, mechanical vibrator. Vibrotactile display elements can be located on the operator's limbs, such as on the hand, fingers, arms, legs, feet, etc. The location of the application of the force may also be specified by the location of a vibrotactile display on the operator's body. Alternatively, the location may be specified by the frequency of a vibrotactile signal

VisIVOWeb: A WWW Environment for Large-Scale Astrophysical Visualization

This article presents a newly developed Web portal called VisIVOWeb that aims to provide the astrophysical community with powerful visualization tools for large-scale data sets in the context of Web 2.0. VisIVOWeb can effectively handle modern numerical simulations and real-world observations. Our open-source software is based on established visualization toolkits offering high-quality rendering algorithms. The underlying data management is discussed with the supported visualization interfaces and movie-making functionality. We introduce VisIVOWeb Network, a robust network of customized Web portals for visual discovery, and VisIVOWeb Connect, a lightweight and efficient solution for seamlessly connecting to existing astrophysical archives. A significant effort has been devoted for ensuring interoperability with existing tools by adhering to IVOA standards. We conclude with a summary of our work and a discussion on future developments

The undesired fellow traveller

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PMUTs Arrays for Structural Health Monitoring of Bolted-Joints

Micro-electro-mechanical systems (MEMS) have enabled new techniques for the miniaturization of sensors suitable for Structural Health Monitoring (SHM) applications. In this study, MEMS-based sensors, specifically Piezoelectric Micromachined Ultrasonic Transducers (PMUT), are used to evaluate and monitor the pre-tensioning of a bolted joint structural system. For bolted joints to function properly, it is essential to maintain a suitable level of pre-tensioning. In this work, an array of PMUTs attached to the head and to the end of a bolt, serve as transmitter and receiver, respectively, in a pitch-catch Ultrasonic Testing (UT) scenario. The primary objective is to detect the Change in Time of Flight (CTOF) of the acoustic wave generated by the PMUT array and propagating along the bolt’s axis between a non-loaded bolt and a bolt in service. To model the pre-tensioning of bolted joints and the transmission of the acoustic wave to and from a group of PMUTs through the bolt, a set of numerical models is created. The CTOF is found to be linearly related to the amount of pre-tensioning. The numerical model is validated through comparisons with the results of a preliminary experimental campaign